The converted mana cost of a spell doesn't change if its controller paid an alternative cost (such as an evoke cost) to cast it.

2015-08-25

Cards with devoid use frames that are variations of the transparent frame traditionally used for Eldrazi. The top part of the card features some color over a background based on the texture of the hedrons that once imprisoned the Eldrazi. This coloration is intended to aid deckbuilding and game play.

2015-08-25

A card with devoid is just colorless. It's not colorless and the colors of mana in its mana cost.

2015-08-25

Other cards and abilities can give a card with devoid color. If that happens, it's just the new color, not that color and colorless.

2015-08-25

Devoid works in all zones, not just on the battlefield.

2015-08-25

If a card loses devoid, it will still be colorless. This is because effects that change an object's color (like the one created by devoid) are considered before the object loses devoid.